Support for a steam generator

ABSTRACT

A nuclear steam generator having a skirt and a circular base plate resting on a plurality of balls to allow lateral movement of the steam generator as the connecting piping expands and contracts due to thermal variations.

Waited States Patent [191 Boyd et a1.

[1 11 3,851,626 [451 Dec. 3, 1974 SUPPORT FOR A STEAM GENERATOR [75] Inventors: John Boyd; Allan K. Hennel, both of [21] Appl. No.5 295,336

Maxwell 122/510 2,201,786 5/1940 Nilson 122/510 3,190,173 6/1965 Pettavel 248/19 3,413,960 12/1968 Feliks et a1. 122/510 Primary Examiner-Kenneth W. Sprague Assistant Examiner-Henry C. Yuen Attorney, Agent, or Firm-F. J. Baehr, Jr.

[57] ABSTRACT A nuclear steam generator having a skirt and a circular base plate resting on a plurality of balls to allow lateral movement of the steam generator as the connecting piping expands and contracts due to thermal variations.

7 Claims, 4 Drawing Figures [52] US. Cl 122/510, 248/19, 165/82, 165/67 [51] Int. Cl. F22b 37/24 [58] Field of Search 122/510; 176/83, 87; 165/67, 68, 81, 82; 248/D1G. l, DIG. 19

[56] References Cited UNITED STATES PATENTS 1,634,084 6/1927 Ruths 122/510 1 SUPPORT FOR A STEAM GENERATOR BACKGROUND OF THE INVENTION This invention relates to nuclear steam generators and heat exchangers and more particularly to a support for such vessels which allow the vessel to move laterally as well as rotate as the connecting piping undergoes thermal changes.

To provide for thermal expansion of the piping connected to steam generators or heat exchangers, a plurality of bends can be provided in the piping so as to reduce the stress applied to the vessel as the piping expands and contracts in response to changes in temperature of the fluid flowing through the pipe. Such vessels may also be mounted to pivot about their axes to reduce the stress introduced by the piping as shown in U.S. Pat. No. 3,413,960. However, providing a plurality of bends increases the pumping costs and reduces the efficiency of the unit and utilizing a system wherein the heat exchanger rotates about its axis also requires a minimum number of bends in the piping.

SUMMARY OF THE INVENTION In general, a support system for a heat exchanger having fluid conduits connected thereto, when made in accordance with this invention, comprises a first generally horizontal planar surface, a second generally planar surface generally parallel the first planar surface, the surfaces having a periphery generally larger than an outer peripheral surface of the heat exchanger, a first ring, a second ring generally smaller than the first ring, the rings being free to move with respect to at least one of the surfaces, and a plurality of balls disposed between the rings, whereby any point on the heat exchanger is free to move in any direction in a plane parallel to the planar surfaces-as the conduits expand and contract due to thermal variations, thus minimizing the stresses on the heat exchanger commonly associated with such thermal variation.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages of this invention will become more apparent from reading the following detailed description in connection with the accompanying drawings, in which:

FIG. 1 is an elevational view of a steam generator;

FIG. 2 is an enlarged partial sectional view of a support for the steam generator;

FIG. 3 is an enlarged partial sectional view taken on line IIIIII of FIG. 2; and

FIG. 4 is an enlarged sectional view showing a modification of the support.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in detail, FIG. 1 shows a heat-exchanger vessel such as a steam generator I having an outer shell 3 and a plurality of pipes or fluid conduits 5 connected thereto. The steam generator 1 is carried on a support structure generally indicated at 7. The support structure 7 comprises a skirt 9 attached to the lower end of the shell 3 and a circular plate or flange plate 1 1 fastened to the lower end of the skirt by welding or other means. A circular base plate 13 rests on a foundation 15 and is disposed generally parallel to the circular plate 11 and generally normal to the axis of the shell 3 so that the facing surfaces 17 and 19, re-

spectively, are generally planar and horizontal. Disposed between the planar surfaces 17 and 19 are a pair of rings 21, 23 of different diameter and disposed between the rings 21 and 23 and the planar surfaces 17 and 19 are a plurality of spherical shaped members or balls 25.

As shown in FIG. 2, the rings 21 and 23 are made of flat bars rolled the easy way forming a circular ring andthe ends are joined by welding or other means to form a ring or cylinder. The diameter of the larger ring 21 is generally larger than the diameter of the smaller ring 23 by an amount slightly larger than twice the diameter of the balls 25. The height of the rings 21 and 23 is slightly less than the diameter of the balls 25, whereby v the rings rest on the planar surface 19 of the base plate 13 and are free to slide thereon.

The circular plate 11 has a plurality of radially extending slots or clearance holes 27 disposed around the outer periphery thereof. A plurality of .1 bolts 29 or other fastening means are anchored in the foundation 15 and extend upwardly therefrom and through the holes 27. Washers 31 and nuts 33 are cooperatively associated with the bolts to prevent the steam generator from tipping when subjected to side forces as would be produced by high winds and the holes 27 and bolts 29 limit its lateral andradial movement.

As shown in FIG. 3, the balls 25 are loosely disposed within the rings 21 and 23 allowing the steam generator 1 to move laterally and to rotate about a plurality of generally vertical axes so that any point on the steam- .generator can move in any direction in a plane parallel to the planar surfaces 17 and 19 to minimize the stresses induced in the shell 3 by the temperature variations in the piping 5.

Circular cover strips 35 may be fastened to the plates to provide simple sealing means which prevent dirt and other foreign material from entering the area wherein the balls contact the plates.

As shown in FIG. 4, the rings 21 and 23 may be sized to accommodate any number of balls 25, whereby the unit load on each ball can be limited so that the plates 11 and 13 need not be heat treated, thus providing a versatile support structure which is economical to produce.

What is claimed is:

a l. A support for a heat exchanger having fluid conduits connected thereto, said support comprising a first generally horizontal planar surface, a second generally planar surface disposed generally parallel to and adjacent said first planar surface, said first planar surface being fastened to said heat exchanger, a base upon which said second planar surface rests, fastening means connecting said first planar surface to said base so as to allow parallel relative movement between said base and said first planar surface, a first ring, a second ring generally smaller than said first ring, said rings being disposed between said planar surfaces and being free to move with respect to at least one of said planar surfaces, and a plurality of spherical shaped members disposed between said rings and said planar surfaces, whereby any point on said heat exchanger is free to move in any direction in a plane parallel to said planar surfaces as said conduit expands and contracts due to thermal variations, thus minimizing the stresses on the heat exchanger associated with such'thermal variation.

6. A support as set forth in claim 1, wherein the difference in diameter of the bands, is greater than twice the diameter of the spherical members.

7. A support as set forth in claim 1 wherein the rings are circular bands having diameters which differ more than twice the diameter of the spherical members and the height of the bands is less than the diameter of the spherical members. 

1. A support for a heat exchanger having fluid conduits connected thereto, said support comprising a first generally horizontal planar surface, a second generally planar surface disposed generally parallel to and adjacent said first planar surface, said first planar surface being fastened to said heat exchanger, a base upon which said second planar surface rests, fastening means connecting said first planar surface to said base so as to allow parallel relative movement between said base and said first planar surface, a first ring, a second ring generally smaller than said first ring, said rings being disposed between said planar surfaces and being free to move with respect to at least one of said planar surfaces, and a plurality of spherical shaped members disposed between said rings and said planar surfaces, whereby any point on said heat exchanger is free to move in any direction in a plane parallel to said planar surfaces as said conduit expands and contracts due to thermal variations, thus minimizing the stresses on the heat exchanger associated with such thermal variation.
 2. A support as set forth in claim 1, wherein the rings slidably engage only one of said planar surfaces.
 3. A support as set forth in claim 1, wherein the heat exchanger has a skirt extending from one end thereof and the first planar surfaces is fastened to said skirt.
 4. A support as set forth in claim 1 wherein the planar surfaces are disposed on circular plates having their center portions removed.
 5. A support as set forth in claim 1, wherein the rings are circular bands.
 6. A support as set forth in claim 1, wherein the difference in diameter of the bands, is greater than twice the diameter of the spherical members.
 7. A support as set forth in claim 1 wherein the rings are circular bands having diameters which differ more than twice the diameter of the spherical members and the height of the bands is less than the diameter of the spherical members. 